1. Field of the Invention
This invention relates to a system, for cooling by outdoor air and cold water, which is suitable for cooling a system generating much heat such as an electronic computer (hereinafter referred to as a computer) or a room in which such a computer is installed, in order to realize an energy savings through the effective use of cold outdoor air.
2. The Prior Art
The recent increase in the number of data processing systems such as the computer has given rise to systems which are high in heat generation density due to the heat generated from the large number of semiconductor elements as the operation rate is much improved and a higher accommodation density is realized. While the heat generation density of an ordinary working office is 10 to 30 kcal/hm.sup.2, that of a computer room is usually as high as 100 to 150 kcal/hm.sup.2. In some cases, it reaches 500 kcal/hm.sup.2 depending on the system layout.
Even in winter with a low outdoor temperature, the amount of heat leaked through the building to the outside is only 1/5 to 1/10 of that generated from computer equipment and therefore the computer room is always cooled, even in mid-winter, to the specified room temperature by operating the cooling system. Moreover, in practice, re-heating, which works against the surplus cooling capability, is attempted by means of an electric heater in order to make the temperature regulation smooth. For this reason, it is completely unreasonable, from an energy saving point of view, to conduct air cooling in the room in mid-winter.